Spectral measuring methods have been proposed by related art which analyze a measurement object, by irradiating the measurement object with light and measuring reflected light from the measurement object. In such spectral measuring methods, an optical apparatus called an integrating sphere is often used, in order for reflected light from the measurement object to converge without leakage. In spectral measurement methods using such an integrating sphere, a measurement procedure exists which is roughly divided such as into the following two types.
(1) Measuring a spectral reflectance of a measurement object, by multilaterally converging irradiated light from light emitting elements on the measurement object, and guiding the reflected light by collimating in front of a spectral filter.
(2) Measuring a spectral reflectance of a measurement object, by multilaterally converging diffused/reflected light from the measurement object on a spectral filter, and guiding the reflected light by collimating in front of the spectral filter.
Further, a white light source such as a Xenon lamp is used as irradiated light, and spectrally dispersing reflected light from a measurement object into several wavelengths with a spectral filter is generally performed.
Further, for example, spectral measuring apparatuses have also been proposed which measure light from a measurement object, without using an integrating sphere, such as in the following Patent Literature 1.